Gravity gradiometer using large momentum transfer beamsplitters

We are currently developing a vertical gravity gradiometer. This new experiment will combine ultracold atoms produced on atom chips and large momentum transfer beamsplitters. Two separated atomic clouds will be interrogated simultaneously to measure the vertical gravity gradient. For that purpose high power laser sources will be developed to get a large separation between the two arms of each interferometer and thus a high sensitivity. We expect a shot noise limited sensitivity of 9.10-12g at ls on a single cloud, and a sensitivity of the gravity gradient measurement of 1, 3.10-1 E at ls, for a separation of lm between the two clouds.